Bootstrap is more than the layout. Its good having good looking buttons by default and cards and toasts and so on with less mucking around.
I find if I dont use a framework like this then I invariably end up creating my own with all these features and wishing I had used bootstrap from the start.
Its not for everyone but for myself (very small teams or just myself and sometimes one other person), its invaluable for getting things done.
What do you mean by 'significant' update? Version 0.90 was released just recently, and there are continual slow and steady updates that come through. For a CSS framework, that seems quite appropriate.
I used a good bit of Bulma prior to jumping on the Tailwind train when it released. While it was a very quick way to get a nice looking page out of the box, the design choice of aggressively over-specifying selectors[0] made it incredibly frustrating to work with, especially paired with utility classes (e.g. Tachyons).
I manage almost 10 projects that use different frameworks and at this point, I'd like to just standardize on something like Bootstrap. So it's less about one vs the other, more what's your comfort level.
But even within that, a couple use BS 3, a couple using BS 4, and now invariably some will use BS 5.
I don't think there's any way around doing a lot of maintenance grunt work nowadays with all this churn and constant API breakage. And it's a tough sell for many customers.
So what is the difference between all these front-end frameworks if they are all dropping down to base HTML + CSS?